Analytical definition of SLA parameters in a video-on-demand service

In this work we propose to use a set of equations to calculate some user's level parameters expressed in the Service Level Agreements (SLA). As example, we particularize these expressions for a Video-on-Demand service (VoD) that adapts its transmission rate to the network conditions. These equations are obtained from an analytical model, which allows obtaining a priori measures of the system performance. This model is simple and computationally calculated. To allow this, we have used well-known methods in Performability analysis [1]: the VoD system is modelled with a Markov-Rewards Chain (MRC); then, this MRC is randomized to be evaluated. The numerical results have been compared with the ones obtained from the testbed of the laboratory platform SSADE (http://ssade.upc.es), showing a good adjustment for the mean value of diverse performance evaluation measures of the VoD system.